Base for adjustable double-ended directional lamp



Dec. 9, 1958 D. A. GROVEMILLER ET AL 2,864,067

BASE FOR ADJUSTABLE DOUBLE-ENDED DIRECTIONAL LAMP Filed. Oct. 51, 1956 hwvefi t'oris: Date A. GrovemiLLev, doe L.ELam,

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United States BASE FOR ADJUSTABLE DUUBLE-ENDED DIRECTIUNAL LAMP Application October 31, 1956, Serial No. GNAQS 8 Claims. (Cl. 33Q-2) The present invention relates to lamp bases and particularly to bases for linear double-ended electric lamps.

The co-pending application of John W. Fulton and Robert A. Kuebler, Serial No. 619,486 of even filing date herewith, which application is assigned to the assignee of the present application, discloses and claims an adjustable linear double-ended fluorescent lamp having preheat type electrodes, bi-pin bases and a directional light output in a plane transverse to its longitudinal axis. The envelope of the lamp is adjustable on its longitudinal axis to change the direction of maximum light output of the lamp without changing the position in holders supporting the lamp of the pins of the bi-pin bases mounted on the ends of the envelope.

The bi-pin bases also disclosed and claimed in the co-pending application each comprises a cylindrical shell having a rim portion which is attached anti-turningly to an end of the lamp envelope and a contact pin assembly mounted for rotation on the shell and including a pair of mutually insulated contact pins and a pin support member holding the pins in parallelpositions. The axis of rotation of the contact pin assembly is coincident with the longitudinal axis of the shell and the pins are symmetrical with the axis of rotation of the assembly and are in a diametral plane of the shell. A pair of such bases is mounted on the lamp envelope, one at each end, with the longitudinal axis of the shell coincident with the longitudinal axis of the lamp envelope. The lamp envelope thus is rotatable on its longitudinal axis with respect to the diametral plane of the pins to orient the directional lamp in lamp holders without moving the pins in the holders.

Short circuiting of the preheat type electrodes of the lamp is avoided by limiting the relative rotation of the envelope and the contact pin assembly to which the current inlead wires for the electrodes are attached. A pair of such wires extend in spaced relation from each end of the lamp envelope. Twisting together of the wires of each pair is prevented by the base of the co-pending application by a pair of kidney-shaped slots in an integral circular Web at one end of the base shell and protrusions on the pin support member of the contact pin assembly. The pin support member consists of two insulating disks clamped to the web of the base shell by the pins which are staked to the disks. The protrusions on the disks extend into and engage the sides of the slots to limit the relative rotation of the shell and the assembly.

The principal object of the present invention is to provide a base of the above type which is of maximum strength, comprises a minimum number of parts and which is readily manufactured and assembled on a mass production basis. Another object of the invention is to provide such a base which is easily mounted in proper position on an end of the tubular envelope of a directional lamp. Further objects and advantages of the invention will appear from the accompanying drawing and the following detailed description of species thereof.

A feature of the base of the present invention is a atent' contact pin assembly including a pin support member consisting of a single disk of organic plastic insulating material in which the ends of the contact pins are molded and which is pivoted on the cylindrical base shell by pin or rivet extending through the center of the disk and the center of the circular web of'the shell and fastening the shell and the assembly together. The contact pin assembly thus may be made separately and fastened as a unit to the base shell.

In the drawing Fig. 1 is a pictorial view of a directional lamp equipped with bases embodying the invention.

Fig. 2 is an enlarged end view of one of the bases shown in Fig. l and as viewed from the envelope engaging end of the base.

Fig. 3 is a sectional view of the base shown in Fig. 2 taken along the line 33 of the Fig. 2 and showing in section an end of the lamp envelope to Which the base is cemented.

Fig. 4 is similar toFig. 3 with the parts thereof rotated and the section of the base taken along the line 4-4 of Fig. 2.

Fig. 5 is an enlarged end-on view of the lamp shown in Fig. l and Fig. 6 is a pictorial view on an enlarged scale of a lamp holder suitable for the lamp equipped with bases of the type illustrated in Figs. 1 to 5.

Referring to Fig. 1, there is shown an elongated tubular double-ended fluorescent lamp having a sealed vitreous light transmitting envelope 1 provided with bi-pin bases 2 and 3 of identical structure attached to the ends thereof. The envelope it transmits light passing through a window 4 defined by an internal reflecting coating 5 provided on the upper portion of its circumference. The common boundaries of the window 4 and the coating 5 are indicated by the lines 6 and 7 in Figs. 1 and 5 of the drawing. The reflecting coating 5 is interposed between the inner surfaceof the envelope 1 and the usual phosphor coating 8 extends around the entire circumference of the envelope 1 so that light produced by phosphor coating 3 is directed by the reflecting coating 5 through the window 4. The lamp thus has a directional characteristic in that it emits more light in the direction in which the window faces than in any other direction. The coating 5 is preferably partially light transmitting.

In structural features other than the bases attached to the ends of the tubular envelope 1 the lamp illustrated is similar to commercial fluorescent lamps having a nondirectional characteristic in that it is provided with an ionizable atmosphere including an inert starting gas, such as argon, at a low pressure and a small quantity of mercury indicated by the droplet 9. The lamp is provided at the ends of the envelope 1 with filamentary electrodes 10, one of which is shown in Figs. 1, 3 and 5, including a tungsten support and electron emissive oxide material on said support. The electrodes are of the hot starting type, that is, requiring either preheating current at starting or continuous heating current during starting and operation. A pair of flexible current leading-in wires 11 and 12 are sealed into the stems 13 at each end of the lamp envelope 1 for conducting preheat and operating current to the electrodes 16.

During operation of the lamp a low pressure mercury vapor discharge between the electrodes 10 within the envelope 1 causes production of resonance radiation at 2537 Angstrom wave length which is converted by the phosphor coating 8 on the inside of the envelope into visible light.

The bi-pin bases 2 and 3 attached to the ends of the envelope 1 are also similar in structure to the bases used heretofore for non-directional fluorescent lamps in that each base comprises a cylindrical cup-shaped metal shell 14 adapted to be cemented at its rim portion to the reduced end portion of the envelope 1, as shown in Fig. 3, and a pair of spaced parallel insulated contact pins 15 and 16 projecting outward in a longitudinal direction from the ends of the based lamp for engagement with lamp holder contacts. The pins 15 and 16 are symmetrically arranged with respect to and are in a diametral plane including the longitudinal axis of the lamp envelope 1 which is usual in fluorescent lamps when the-bases are properly mounted on the envelope ends.

The bases 2 and 3 differ from the known bases in commercial use in that the contact pins 15 and 16 of each base are included in an assembly which also includes a single disk 17 of organic plastic insulating material which is pivoted at its center to the center of an integral circular web 19 provided on the shell 14. The pivot pin is in the form of a rivet 18 which fastens the shell 14 and the assembly including disk 17 together in such manner as to allow relative rotary displacements thereof. The position of the window 4 of a lamp provided with a pair of bases 2 and 3 mounted on the ends of its envelope 1 with the shell 14 of each base cemented anti-turningly thereto in the usual manner, as shown in Fig. 3, and with the axis of relative rotation of the shell and the contact pin assembly of each base coincident with the longitudinal axis of the envelope 1 may be changed while the lamp is mounted in lamp holders and without changing the position of the contact pins in the holders by rotating the envelope 1 on its longitudinal axis. The higher light output side of the lamp having the sired direction.

In order to avoid twisting together of the leading-in wires 11 and 12 of the lamp, which, would short-circuit the heating current to the electrodes 10, the relative rotary displacement of the shell 14 afiixed to the envelope 1 and the disk 17 on which the pins 15 and 16 are fixedly mounted by molding their ends into the disk is limited to an angular distance of approximately 110. This is accomplished by the provision of diametrically opposed arcuate slots 20 and 21 (Figs. 2 and in the circular web 19 of the shell 14 and cylindrical, hollow protrusions 22 and 23 on the side of the disk 17 engaging the web 19. The protrusions 22 and 23 extend into the slots 20 and 21 the ends of which thus serve as stops for limiting the relative rotary movements of these base components.

The inner surface of the protrusions 22 and 23 define a conical passage (Figs. 2 and 3) leading into the bores of the tubular pins and 16 to facilitate threading of the wires 11 and 12 into the pins prior to attaching the wires to the pins during assembly of the base and the envelope 1. To facilitate this threading operation, the slots and 21 are substantially greater in width than the diameter of the wires 11 and 12. Also, the outer diameter of the protrusions 22 and 23 and the largest diameter part of the conical passages in the protrusions closely approach the width of the slots. This structure also provides a wide spacing between the inlead wires 11 and 12 and the sides of the slots for electrically insulating purposes. The protrusions 22 and 23 of the insulating disk 17 extend inward of the base beyond the sides of the slots,.as shown in Fig. 3, to interpose insulating material between the said wires and the metal of the shell 14. This also increases the surface distance between the metal shell and the ends of the pins 15 and 16 molded into the insulating disk 17 to provide an increased safety factor for the base. The sides of the slots 20 and 21 are constituted by flanges on the web which extend slightly inward of the shell 14 and at right angles to the web 19 as shown in Figs. 3 and 4 to strengthen the latter.

As explained in the co-pending application referred to above, in mounting the base on the end of the envelope 1 it is advantageous to have the base shell 14 and the contact pin assembly at their mid-point of rotation and the diametral plane of the contact pins and the common plane of the electrodes 10 and the inlead wires 11 and 12 at each window 4 thus may be faced in a deend of the envelope coincident, as shown in Fig. 5, in which the line AB indicates the position of these planes. The envelope of a based lamp then may be rotated with respect to the plane of the pins an angular distance of 55 from the mid-point of rotation in either direction Without twisting the wires 11 and 12 together.

It is advantageous also for obtaining a desired light distribution as described in the co-pending application, to correlate the position of the median plane C-D of the window 4 (Fig. 5) and the diametral plane AB of the pins 15 and 16 in such manner that these planes are at an angle of approximately 40 with respect to each other When the shell 14 and the assembly including disk 17 are at their mid-point of rotation.

For convenience in mounting the bases 2 and 3 on the envelope 1 with the diametral planes of the pins and the median plane of the window properly correlated, an integral pointer 24 is provided on the disk 17, which pointer is at right angles to the diametral plane AB of the pins. A detent comprised of a pawl constituted by a dent 25 in web 19 of the shell 14 of each of the bases and an armately arranged series of notches 26 in the web engaging face of the disk 17 is provided to hold the shell and the disk at their mid-point of rotation while mounting the bases on the lamp envelope. Also the shell 14 of each of the bases 2 and 3 is provided with two radially extending ribs-27 and 28 (Fig. 5) which facilitate mounting of the bases in proper position with respect to the window 4 by providing a visual indication on the outside of each base of the position of the internal parts of the base. For this purpose, the ribs 27 and 28 are spaced apart an angular distance of 40 from each other and are symmetrically arranged with respect to a plane, such as the plane E-F normal to a diametral plane of the shell, such as the plane A---B, including the mid-points of the slots 20 and 21.

Thus, as shown in Fig. 5, when the pointer 24 is positioned midway between the ribs 27 and 28, the disk 17 and the shell 14 are at the mid-point of their relative roration. With the pointer 24 so positioned on each base,

the shell of the base 2 is cemented to the end of envelope 1 with the rib 27 in alignment with the boundary 6 of the window 4 and the rib 28 located between the boundaries 6 and '7. The base 3 of identical structure is cemented to the opposite end of the envelope 1 with the rib 28 in line with the boundary 6 and the rib 27 between v the boundaries 6 and 7. With the bases so mounted on the ends of the envelope 1 the latter is rotatable on its longitudinal axis an angular distance of 55 in either direction with respect to the common diametral plane of the pins 15 and 16 on the bases 2 and 3. In Fig. 5 the position of the boundaries 6 and 7 with the envelope 1 rotated the whole distance in either direction is indicated at 6', 6 and 7, 7".

The holding force exerted by the detent 25, 26 is supplemented by forcing the disk 17 against the web 19 of the shell 14. For this purpose the part of the web between the slots 20 and 21, to which part the disk 17 is riveted, is sprung inward of the shell slightly before the stiff disk 17 is riveted thereto. In riveting the disk and the shell together the inwardly sprung web part of the shell is flexed-slightly in an outward direction so that on completion of the riveting the disk is pulled inward against and frietionally engages the outer portion of the web of the shell. The combined holding force of these base parts should be less than the torque required to turn the pins in the holders for the lamps.

The web 19 of the shell 14 is recessed slightly into the shell to form a cup which receives the disk 17. The

wall 29 thus formed in the interior of the shell (Figs. 3

and 4) is available as a dam for the basing cement when an excess of the cement is inadvertently applied to the.

inner surface of the shell and thus serves to hold the cement in the manufacture of the lamp in the usual manner.

proper position until the latter is hardened in i The lamp holder 30 shown on an enlarged scale in Pig. 6 of the drawing is of the well-known type for accommodating oi-pin fluorescent lamps and may be constructed in accordance with the Marshaus Reissue Patent No. 21,545 of August 27, 1940, and the Bryant Patent No. 2,292,043, both of which patents are assigned to the assignee of this application. A lamp holder of this type may be provided for each end of the lamp and the holders are spaced apart a distance such that the front face of the insulating housing 32 having the opening 33 butts against the disk 17 on each of the bases 2 and 3 of a mounted lamp.

The housing 3?. of the lamp holder is of suitable insulating plastic and the opening 33 is of generally circularform and merges with a slot 34- extending from the opening to the outer edge of the housing. An insulating guide stud 35 projects forward substantially to the plane of the opening 33 and is provided with a groove 36 in alignment with the slot 34. Spring contact blades 37, 38 are mounted in spaced relation on opposite sides of the guide stud 3d for engagement with the contact pins of the lamp.

ln mounting the lamp between holders having the slot in each holder directed downward, the contact pins on each of the bases 2 and 3 are moved upward in alignment through the slot 3d and the groove 36 until the innermost pin engages the wall of the opening 3?; thereafter, the lamp is rotated 90 on its longitudinal axis to move the contact pins into engagement with the slightly ii-shaped parts of the contact members 37, 325 located in a plane normal to the slot 34 and the groove as.

The pointer 24, being normal to the diametral plane of the pins 15 and i6 is useful also in mounting the lamp in the holders by indicating the position of the pins in the holders. For example, with holders of the type shown in l, in which the pin engaging parts of the holder contacts are in a plane normal to the pin receiving slot and groove in the holder, the lamp is rotated in the holders until the pointer 24 on each of the bases 2 and 3 coincides with the slot 34 in each of the holders or is in a position 180 from the slot depending upon the desired position of the window 4. In either position, the pointer 24' indicates that the pins 15 and 16 are properly engaged with the V-shaped parts of the holder contacts 37 and 38.

When inserting the lamp in its holder it is convenient to first rotate the pin assemblies on both ends of the lamp an angular distance of 55 from their midpoint of rotation in the same direction, which may be either clockwise or counter-clockwise, to overcome the holding force of the detent 25, 26 and to bring the protrusions 22, 23 against the ends of the slots 20, 21. The lamp is then moved transversely of its longitudinal axis upward into the holders and then rotated around its longitudinal axis as described above to bring the contact pins into engagement with the holder contacts. Preferably, the direction in which the lamp is rotated to seat it in the holders is opposite the direction in which the pin assemblies were rotated in preparing to mount the lamp. The protrusions are thus held at the same ends of the slots while rotating the lamp though this is not essential.

After the lamp has been seated in its holders in the manner described above, angular adjustments of the window 4 with respect to the diametral plane of the pins 15 and 16 may be made.

While a species of the invention has been shown in the drawing and described above, it will be understood, of course, that such showing and description is for illustrative purposes and that numerous changes in the form and details of the base may be made by those skilled in the art without departing from the invention as defined in the appended claims, for example, other markings may be used on the base shell in place of ribs 27 and 28 as visual aids in properly positioning the bases on the envelope.

6 What we claim as new and desire to secure by Letters Patent of the United States are:

1-. A lamp base comprising a cylindrical shell having.v

a rim portion for attachment anti-turningly to an end of a lamp envelope and an integral circular web at the end thereof opposite said rim, a contact pin assembly comprising a pair of mutually insulated contact pins, a.

support holding said pins in spaced parallel positions and a rivet means at the center of said web and said support fastening said assembly to said shell for pivotal movement on said shell with its pivotal axis coincident with the longitudinal axis of said shell, said pins being symmetrically arranged with respect to the longitudinal axis and in a diametral plane of said shell, said pin support and the web of said shell having interengageable parts constituting positive stop'means for limiting the relative rotation of said contact pin assembly and said shell.

2. A lamp base comprising a cylindrical shell having a rim portion for attachment anti-turningly to an end of a lamp envelope and an integral circular web at the end thereof opposite said rim, said web having a pair of opposed arcuate slots therein having a center of curvature coincident with the center of said web, a contact pin assembly comprising a pair of mutually insulated con.- tact pins and a support holding said pins in spaced parallel positions, said support consisting of a disk of in sulating material pivoted on said web with its pivotal axis coincident with the longitudinal axis of said shell, said pins being symmetrically arranged with respect to the longitudinal axis and in a diametral plane of said shell, said disk having protrusions aligned with said pins and extending freely into said slots, the parts of said protrusions within said slots extending longitudinally of said slots a distance substantially less than the length of said slots whereby said shell and said pin assembly are relatively rotatable around the said pivotal axis and the said protrusions and the ends of said slots limit the relative rotation of said shell and said assembly.

3. A lamp base comprising a cylindrical shell having a rim portion for attachment anti-turningly to an end of a lamp envelope and an integral circular web at the end thereof opposite said rim, said web having a pair of opposed arcuate slots therein having a center of curvature coincident with the center of said web, a contact pin assembly comprising a pair of mutually insulated contact pins and a support holding said pins in spaced parallel positions, said support consisting of a disk of insulating material pivoted on said webwith its pivotal axis coincident with the longitudinal axis of said shell, said pins being symmetrically arranged with respect to the'lo-ngitudinal axis and in a diametral plane of said shell, said disk having hollow protrusions defining conical passages communicating with said pins to facilitate attachment of leading-in-wires to said pins, said protrusions being aligned with said pins and extending freely into said slots, the parts of said protrusions within said slots extending longitudinally of said slots a distance substantially less than the length of said slots whereby said shell and said pin assembly are relatively rotatable around the said pivotal axis and the said protrusions and the ends of said'slots limit the relative rotation of said shell and said assembly.

4. A lamp base comprising a cylindrical shell having a rim portion for attachment anti-turningly to an end of a lamp envelope and an integral circular web at the end thereof opposite said rim, said web having a pair of opposed arcuate slots therein having a center of curvature coincident with the center of said web, the sides of said slots being constituted by flanges on said web, said flanges extending inwardly of said shell and normal to said web to strengthen said web, a contact pin assembly comprising a pair of mutually insulated contact pins and a support holding said pins in spaced parallel positions, said support consisting of a disk of insulating material pivoted on said web with its pivotal axis coincident with the longitudinal axis of said shell, said pins being symmetrically arranged with respect to the longitudinal axis and in a diametral plane of said shell, said disk having protrusions aligned with said pins and extending freely into said slots, the parts of said protrusions within said slots extending longitudinally of said slots a distance substantially less than the length of said slots whereby said shell and said pin assembly are relatively rotatable around the said pivotal axis and the said protrusions and the ends of said slots limit the relative rotation of said shell and said assembly.

5. A lamp base comprising a cylindrical shell having a rim portion for attachment anti-turningly to an end of a lamp envelope and an integral circular web at the end thereof opposite said rim, said web having a pair of opposed arcuate slots therein having a center of curvature coincident with the center of said web, a contact pin' assembly comprising a pair of mutually insulated contact pins and a support holding said pins in spaced parallel positions, said support consisting of a disk of insulating material pivoted on said web with its pivotal axis coincident with the longitudinal axis of said shell, said pins being symmetrically arranged with respect to the longitudinal axis and in a diametral plane of said shell, said disk having protrusions aligned with said pins and extending freely into said slots, the parts of said protrusions within said slots extending longitudinally of said slots a distance substantially less than the length of said slots whereby said shell and said pin assembly are relatively rotatable around the said pivotal axis and the said protrusions and the ends of said slots limit the relative rotation of said shell and said assembly, the portion of said web between said slots being sprung inwardly of said shell and said disk being pivoted on the sprung portion of said web and clamped thereby against said web whereby to exert a holding force against. casual relative rotation of said shell and said assembly.

6. A lamp base comprising a cylindrical shell having a rim portion for attachment anti-turningly to an end of a lamp envelope and an integral circular web at the end thereof opposite said rim, said web being recessed into said shell to form a retaining wall for basing cement in the interior of said shell and having a pair of opposed arcuate slots therein having a center of curvature coincident with the center of said web, a contact pin assembly compris ing a pair of mutually insulated contact pins and a support holding said pins in spaced parallel positions, said support consisting of a disk of insulating material pivoted on said web with its pivotal axis coincident with the longitudinal axis of said shell, said pins being symmetrically arranged with respect to the longitudinal axis and in a diametral plane of said shell, said disk having protrusions aligned with said pins and extending freely into said slots, the parts of said protrusions within said slots extending longitudinally of said slots a distance substantially less than the length of said slots whereby said shell' and said pin assembly are relatively rotatable around the said pivotal axis and the said protrusions and the ends of said slots limit the relative rotation of said shell and said assembly.

7. A lamp base comprising a cylindrical shell having a rim portion for attachment anti-turningly to an end of a lamp envelope and an integral circular web at the end thereof opposite said rim, said web having a pair of opposed arcuate slots therein having a center of curvature coincident with the center of said web, a contact pin assembly comprising a pair of mutually insulated contact pins and a support holding said pins in spaced parallel positions, said support consisting of a disk of insulating material pivoted on said web with its pivotal axis coincident with the longitudinal axis of said shell, said pins 7 being symmetrically arranged with respect to the longitudinal axis and in a diametral plane of said shell, said disk having protrusions aligned with said pins and extending freely into said slots, the parts of said protrusions within said slots extending longitudinally of said slots a distance substantially less than the length of said slots whereby said shell and said pin assembly are relatively rotatable around the said pivotal axis and the said protrusions and the ends of said slots limit the relative rotation of said shell and said assembly, said disk having a pointer thereon indicating the position of a plane including said pins and said shell having indicia thereon indicating the position of a plane including the midpoint of said slots to facilitate mounting of said base on a lamp envelope with said shell and said assembly at predetermined relative rotary positions.

8. A lamp base comprising a cylindrical shell having a rim portion for attachment anti-turningly to an end of a lamp envelope and a circular web at the end thereof opposite said rim, said Web having a pair of opposed arcuate slots therein having a center of curvature coincident with the center of said web, the sides of said slots being constituted by flanges on said web, said flanges extending inwardly of said shell and normal to said Web to strengthen said web, a contact pin assembly comprising a pair of mutually insulated contact pins and a support holding said pins in spaced parallel positions, said support consisting of a disk of insulating material pivoted on said web with its pivotal axis coincident with the longitudinal axis of said shell, said pins being symmetrically arranged with respect to the longitudinal axis and in a diametral plane of said shell, said disk having hollow protrusions defining conical passages communicating with said pins to facilitate attachment of leading-in wires to said pins, said protrusions being aligned with said pins and extending freely into said slots a sufiicient distance to insulate from said shell leading-in wires attached to said pins, the parts of said protrusions within said slots extending longitudinally of said slots a distance substantially less than the length of saidv slots whereby said shell and said pin assembly are relatively rotatable around the said pivotal axis and the said protrusions and the ends of said slots limit the relative rotation of said shell and said assembly.

References Cited in the file of this patent UNITED STATES PATENTS 858,152 Coffman June 25, 1907 1,934,799 Gunby Nov. 14, 1933 1,955,652 Pearson Apr. 17, 1934 2,055,999 Caldwell Sept. 29, 1936 2,328,212 Heiner Aug. 31, 1943 2,659,836 Germer Nov. 17, 1953 

